Disphyma australe subsp. australe
Common name
horokaka, native ice plant, New Zealand ice plant
Synonyms
Mesembryanthemum australe W.T.Aiton
Family
Aizoaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Herbs - Dicotyledons other than Composites
Chromosome number
2n = 36
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
Distribution
Endemic. New Zealand: Three Kings, North, South, Stewart and Chatham Islands
Habitat
Coastal (rarely inland). Mostly on cliff faces, rock stacks, and boulder/cobble beaches, more rarely in saltmarsh and estuaries. Often in petrel scrub on offshore islands, and extending into coastal forest around petrel burrows. Occasionally on limestone or sandstone cliffs in lowland forest (Western Waikato).
Features
Trailing, succulent herb. Stem terete, glabrous. Short shoots prostrate, rooting freely at nodes. Leaves 3-angled, linear-lanceolate to oblong, acute, often mucronate, tapering to connate base, 6-40 × 4-9 mm; margins entire, smooth, very rarely with a few papillae towards the distal end of the keel. Flowers 20-40 mm diameter. Sepal keel entire, smooth. Petals uniformly white to deep pink, in 3-5 rows, 10-30 mm long. Stamens 4-6 mm long; inner filaments hairy at base. Stigmas (5)-6-8-(10). Capsule valves 5-10, with parallel or ± divergent expanding keels; placental tubercle rounded or 0. Seeds brown, obovoid, rugose, c. 1 mm long.
Similar taxa
Distinguished from the other New Zealand species by the leaf margin and sepal keel smooth (very rarely papillate near the apex), 3-angled, linear-lanceolate to oblong, acute and often mucronate leaves, and petals in 3-5 rows. The Kermadec endemic subsp. stricticaule differs by the short shoots mostly ascending, rarely rooting at nodes, papillate leaves and sepal keels, and 5 rarely 6 capsule valves.
Flowering
Present throughout the year
Flower colours
Red/Pink, Violet/Purple
Fruiting
Present throughout the year
Life cycle
Fleshy capsules are dispersed by frugivory and possibly wind and water (Thorsen et al., 2009).
Propagation technique
Easy from rooted pieces and fresh seed. Does well in free draining soil within a sunny site. Not fussy about soil fertility or moisture regime. Some cultivar selection might be necessary as there is a diverse range of foliage colours, and flower colour ranges from white to fully pink.
Etymology
disphyma: Two-nodule
australe: Southern, from the Latin australis
Attribution
Description modified from: Webb, C. J.; Sykes, W. R.; Garnock-Jones, P. J. 1988: Flora of New Zealand. Vol. IV. Naturalised Pteridophytes, Gymnosperms, Dicotyledons. 4. Christchurch, New Zealand, Botany Division, D.S.I.R. Forms natural intergeneric hybrids with both Carpobrotus chilensis and C. edulis.
References and further reading
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285-309
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Disphyma australe subsp. australe Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/disphyma-australe-subsp-australe/ (Date website was queried)